With increasing emphasis on the need to provide low cost energy efficient housing and buildings, utilization of expanded plastic material and panels for insulation is becoming more prevalent. Such plastic materials are generally applied to conventional construction, or prefabricated in the form of lightweight composite panels applied to conventional on-site or prefabricated structures, thereby generally increasing somewhat the cost of such construction.
Referring to conventional multifloor structures, these generally incorporate prefabricated panel elements as enclosure material or sheathing, the structure itself being erected in situ using standard structural sections or forming and pouring concrete around reinforcing steel to form reinforced concrete structural elements.
Prefabricated expanded plastic material is also presently used as a filler between sheet metal surfaces, plane or corrugated, affixed to opposing sides of the plastic. Although this solution provides, if properly installed, both required rigidity and thermal properties, it is not particularly applicable to residential construction. The general use of the prefabricated plastic panel or sheet is therefore presently confined to thermal applications and reduction of energy costs, and has done little or nothing to lower initial construction costs. Conventional structural costs may even be increased as a result of accommodating these prefabricated elements to achieve thermal energy savings.